Spin-dependent tunneling between individual superconducting bound states
Spin-dependent tunneling between individual superconducting bound states
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DOI：
10.1103/physrevresearch.3.l032008
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发表时间：
2021-07-08
影响因子：
4.2
通讯作者：
Ast, Christian R.
中科院分区：
文献类型：
--
作者：
Huang, Haonan;Senkpiel, Jacob;Ast, Christian R.
超导体上的磁性杂质在超导能隙内诱导出离散的束缚能级，称为Yu-Shiba-Rusinov（YSR）态。YSR能级是完全自旋极化的，使得YSR状态之间的隧穿取决于它们的相对自旋取向。在这里，我们使用扫描隧道光谱，以解决两个YSR状态之间的隧道过程中的自旋动力学实验提取之间的角度。为此，我们利用测量中的热激活和直接光谱特征的比率来直接提取两个YSR状态之间的相对自旋取向。我们发现自由旋转的自旋下降到7 mK，表明纯顺磁性的杂质。这种非共线的自旋排列不仅对于产生马约拉纳束缚态是必不可少的，而且作为操纵和移动马约拉纳态到尖端的前景。
Magnetic impurities on superconductors induce discrete bound levels inside the superconducting gap, known as Yu-Shiba-Rusinov (YSR) states. YSR levels are fully spin polarized such that the tunneling between YSR states depends on their relative spin orientation. Here, we use scanning tunneling spectroscopy to resolve the spin dynamics in the tunneling process between two YSR states by experimentally extracting the angle between the spins. To this end, we exploit the ratio of thermally activated and direct spectral features in the measurement to directly extract the relative spin orientation between the two YSR states. We find freely rotating spins down to 7 mK, indicating a purely paramagnetic nature of the impurities. Such a noncollinear spin alignment is essential not only for producing Majorana bound states but also as an outlook manipulating and moving the Majorana state onto the tip.